256 SYMBIOGENESIS 



habitually shows itself at the same time in continuity and in 

 complication." 



Such a sweeping view is roughly correct and congruous 

 with the belief that evolution is a great fact, although it is not 

 backed up by a satisfactory account of the inter-relations 

 between organism and environment. 



As has been said before, gratitude is due to both Spencer 

 and Darwin for having made their great and sweeping state- 

 ments, although, in so far as they could not fully establish 

 them in their day, the statements had to remain somewhat 

 premature. Prof. Bateson, as we have previously seen, so far 

 as Darwin is concerned, in speaking of the difficulties pre- 

 sented by heredity, specifically acknowledges this, and even 

 Samuel Butler, the greatest of Darwin's opponents, acknow- 

 ledged Darwin's merit: "He found the world believing in 

 fixity of species, and left it believing in spite of his own 

 doctrine in descent with modification." 



" Palmam qui meruit ferat." 



Similarly the reading of Spencer's works must have 

 inclined many to believe in progress and in the inevitability 

 of progress in spite of the inadequacy of some of his 

 explanatory methods. Spencer, indeed, and as we have 

 previously seen, goes so far as to recognise that, generally 

 speaking, "as the life becomes higher, the environment itself 

 becomes more complex." He thinks that a zoophyte rooted to 

 a stone need undergo no internal changes such as those by 

 which the caterpillar meets the varying effects of gravitation 

 while creeping over and under the leaves. This is the old 

 " post hoc ergo propter hoc " fallacy in which Darwin also 

 was fond of indulging, as if organisms were not also them- 

 selves responsible, as it were, for their environment and their 

 biological conduct had no place in the improvement of the 

 environment. 



A sessile animal, however, is usually a degenerate animal, 

 being commonly thereby divorced from the possibility of 

 symbiosis, and the changes it undergoes are consequently of the 



